I have a nexus 7 on Android 4.2.1 which I have already rooted. I'm thinking of maybe playing around a bit with customizing Android (mainly kernals) to see what all the fuss is (along with the fact that the tegra 3 gpu isn't as fast as it should be for some games -> Overclock tiem!).

Now, the thing is that i've already set up my tablet in a way that I like, so i'm thinking if I mess around with android, i'll have to set up everything again.

A few questions:

1. I've heard that you can backup your apps and data using different software (like Titanium Backup or Windows software like Wug's Nexus Root Toolkit) and restore them later. If I do this, will it completely restore all apps and their settings, including apps like gmail, email clients, skype, etc? or will it only restore user apps and data? Please consider that I probably WON'T be installing a custom ROM.

2. I want to try a custom kernel to overclock my gpu primarily. How do I go about on doing this? Do I just flash the kernel using CWM recovery or will I need to perform a factory reset (which is why I asked the first question)?

I know these are n00b questions but i'd really appreciate it if someone could point me in the right direction.

1. The best thing to do (if you have an unlocked bootloader) is to do a nandroid backup... its like a clone of your system (like norton ghost for example) but yes, those apps you mentioned should work fine.

I am relatively new too. I never figured out how to root any of my Google Nexus devices. As far as backing up, I thought just copying all the folders onto your computer was enough. I'm not sure that would backup your apps though...

1. The best thing to do (if you have an unlocked bootloader) is to do a nandroid backup... its like a clone of your system (like norton ghost for example) but yes, those apps you mentioned should work fine.

I know that...but that's not what i'm looking for. What I meant was that what if I "reformatted" my tablet OS (i.e. factory reset) and then wanted to "restore" my user apps and the app settings I had previously without having to set them up again (like reformatting a PC with a fresh OS install but restore apps and their settings as they were set up before). Is that possible?

2. just flash the new kernel and wipe the dalvik cache

Will that wipe any app settings (i.e. logins for email/gmail, system settings, etc)?

I am relatively new too. I never figured out how to root any of my Google Nexus devices. As far as backing up, I thought just copying all the folders onto your computer was enough. I'm not sure that would backup your apps though...

Quite easily actually. Head over to XDA forums and you'll find one-click nexus toolkits that guide you through the process and do everything for you. Rooting requires bootloader unlock, and that wipes everything on your device (but the toolkits backup your stuff...so no worries there!).

I know that...but that's not what i'm looking for. What I meant was that what if I "reformatted" my tablet OS (i.e. factory reset) and then wanted to "restore" my user apps and the app settings I had previously without having to set them up again (like reformatting a PC with a fresh OS install but restore apps and their settings as they were set up before). Is that possible?

Will that wipe any app settings (i.e. logins for email/gmail, system settings, etc)?

Quite easily actually. Head over to XDA forums and you'll find one-click nexus toolkits that guide you through the process and do everything for you. Rooting requires bootloader unlock, and that wipes everything on your device (but the toolkits backup your stuff...so no worries there!).

Sorry, I wrote up a reply to this topic but apparently I never posted it. What you want is Titanium Backup. Go ahead and download it. Hell, go ahead and pay for it. It'll be one of your most valuable apps and the pay version does add features. Anyway, this will backup your apps and their current states so that you can recover them back to the way they were on a fresh OS install.

Flashing a kernel won't wipe your system. You'll want to wipe your caches after you flash the new kernel though, but that won't be noticeable to you aside from a quick optimization of apps when you boot.

And what exactly is the reason to root the device? I only want to because the PS3 controller app needs root access for whatever reason.

Well, you root for a number of reasons, but not everyone has a reason to need to. One of the biggest reasons would be for apps like I mentioned above, Titanium Backup. Other reasons for root might be using a USB drive with USB OTG, modifying more advanced settings (DPI for example), and a number of other features like the PS3 controller you mention. It's Linux, so it's the same as if you needed root access on Linux, or even like having Admin access on a Windows box. It's not a complicated process though, so if you even have one reason like you mentioned above, then I think you have enough reason to root.

Sorry, I wrote up a reply to this topic but apparently I never posted it. What you want is Titanium Backup. Go ahead and download it. Hell, go ahead and pay for it. It'll be one of your most valuable apps and the pay version does add features. Anyway, this will backup your apps and their current states so that you can recover them back to the way they were on a fresh OS install.

Even google app settings like the built in email client and gmail app (logins and app settings)? Even paid apps?

Flashing a kernel won't wipe your system. You'll want to wipe your caches after you flash the new kernel though, but that won't be noticeable to you aside from a quick optimization of apps when you boot.

Oh I meant wiping the dalvik cache and any other caches (are there any other caches?). Will that have any adverse effects (i.e. will it wipe anything)?

Sorry, I wrote up a reply to this topic but apparently I never posted it. What you want is Titanium Backup. Go ahead and download it. Hell, go ahead and pay for it. It'll be one of your most valuable apps and the pay version does add features. Anyway, this will backup your apps and their current states so that you can recover them back to the way they were on a fresh OS install.

Flashing a kernel won't wipe your system. You'll want to wipe your caches after you flash the new kernel though, but that won't be noticeable to you aside from a quick optimization of apps when you boot.

Well, you root for a number of reasons, but not everyone has a reason to need to. One of the biggest reasons would be for apps like I mentioned above, Titanium Backup. Other reasons for root might be using a USB drive with USB OTG, modifying more advanced settings (DPI for example), and a number of other features like the PS3 controller you mention. It's Linux, so it's the same as if you needed root access on Linux, or even like having Admin access on a Windows box. It's not a complicated process though, so if you even have one reason like you mentioned above, then I think you have enough reason to root.

Ah, I didn't realize it was Linux based so your analogy makes perfect sense, thanks!

Even google app settings like the built in email client and gmail app (logins and app settings)? Even paid apps?

Oh I meant wiping the dalvik cache and any other caches (are there any other caches?). Will that have any adverse effects (i.e. will it wipe anything)?

You have to understand how Android sets itself up on the phone. It builds partitions and keeps everything completely separate. If you flash a kernel, it won't delete or overwrite ANYTHING but the kernel. The "system" partition you'll see referenced in the places such as the bootloader is where the Android OS is installed. Wiping this means you have no Android OS, and writing over it with a new ROM means you have a new OS. The "data" partition is your customizations on top of the OS. For example, /system/app is where the built in OS apps go, apps you can't delete like bloatware, etc. /data/app is where your user installed apps are. So whenever you want to wipe the OS, wipe system. Whenever you want to wipe your customizations (factory reset), wipe data. Now, doing a factory reset or /data/ wipe would be recommended when swapping between different ROMs usually, but no wipes are typically going to be necessary for a kernel. Cache is just that, a cache, so if you wipe it, you won't wipe anything noticeable. The only thing you'll see is it reoptimizing the apps when you boot back up after cache clear.

You have to understand how Android sets itself up on the phone. It builds partitions and keeps everything completely separate. If you flash a kernel, it won't delete or overwrite ANYTHING but the kernel. The "system" partition you'll see referenced in the places such as the bootloader is where the Android OS is installed. Wiping this means you have no Android OS, and writing over it with a new ROM means you have a new OS. The "data" partition is your customizations on top of the OS. For example, /system/app is where the built in OS apps go, apps you can't delete like bloatware, etc. /data/app is where your user installed apps are. So whenever you want to wipe the OS, wipe system. Whenever you want to wipe your customizations (factory reset), wipe data. Now, doing a factory reset or /data/ wipe would be recommended when swapping between different ROMs usually, but no wipes are typically going to be necessary for a kernel. Cache is just that, a cache, so if you wipe it, you won't wipe anything noticeable. The only thing you'll see is it reoptimizing the apps when you boot back up after cache clear.

Thank you for explaining it so well and, above all, bearing with me .

One last question. If I an android update comes out, and I have flashed a custom kernel, will I have to reflash the stock rom or could I just reflash the stock kernel and update?

One last question. If I an android update comes out, and I have flashed a custom kernel, will I have to reflash the stock rom or could I just reflash the stock kernel and update?

Well, if you're just using a custom kernel and an update comes out to update Android, it'll overwrite your custom kernel with it's new kernel, and your kernel likely won't work on the new version anyway. Most of the time OS upgrades require an entirely new kernel built for that OS version. In that case, you'll have to find a kernel built for the new OS update. You'll probably also want to wait until the XDA guys get the OTA update and strip out anything you don't want from it. Sometimes they patch root in updates and a straight OTA update may leave you with no root until a new exploit is found. Just read up on some of the threads on XDA and they should guide you in the right direction.